Thought I'd check out the hype. Great burger, had the "Big Smash" which hangs out the side of the bun a bit. Very, very juicy. Great flavor. The rosemary "Smash Fries" are very good as well. Onion bun was good. It's not so much greasy as it is juicy, but I could see how it can get messy.
The owners were having a little conference at the table next to us and treated us to try samples of the black-bean burger. While the patty itself is vegetarian, it's cooked on the same flat-top as the meat burgers, so they are trying to figure out how to declare that on the menu board. The burger was very good, great black bean flavor and actually held up pretty well on the bun.
Service was excellent and pretty quick. We'll definitely add this to our lunch rotation.